Lignin is the second most abundant biomass and the only natural source of aromatic hydrocarbons. The great challenge of the low-level utility of lignin remains for the biochemical industry. Recently, grafting modification of lignin via atom transfer radical polymerization(ATRP) has attracted much interest as an important improvement strategy for lignin. Varied kinds of lignin-based copolymers with different properties are synthesized via ATRP. This review summarizes the progress of grafting modification of lignin via ATRP, including the monomers, catalysts, copolymer structures and properties. Moreover, the outlook and challenges for lignin-based copolymers are discussed.